Is there any way to troubleshoot the XYZ switch (gear position switch). My 2000 LR Disco II is in the "limp" mode, M & S lights flashing. The "D" lights adjacent to the shifter are flashing and it stays in "D" and does not downshift when driving. I checked the battery and alternator. The battery is new, but I did remove the terminals and clean and retighten them. No help. I then checked the alternator which is putting out a solid 14 volts. I was told to see if the XYZ switch may be bad. I've removed it. It looks OK mechanically,,,nothing physically broken or damaged. So how can I check this thing out before I throw down big bucks for a new one that I might not need??

Matt B.